Memory system and operating method thereof

A memory system comprising:

• a memory device;
• and
• a memory controller for communicating with the memory device and controlling the memory device,
• wherein the memory controller comprises a first memory, a second memory and a buffer circuit, and
• wherein the memory controller:
• stores target data, which is data to be programmed in the memory device, in the first memory,
• selectively stores the target data in the second memory,
• programs the target data stored in the first memory into the memory device, and
• reprograms the target data stored in the first memory or the second memory into the memory device when the programming of the target data stored in the first memory into the memory device fails, and
• wherein the memory controller selectively stores the target data in the second memory by providing the target data to the buffer circuit for the buffer circuit to input the target data into the second memory or discard the target data.